Hi i want to perform double looping for different values of i and j as follows.. when i remove the summation sign it works, but no output obtained otherwise.

for j from 0 to 4, for i from 1 to 4 do u[i,1]:=-h*(∑)int(K2ij*gj(t),t=0..x)od;

Each K2ij and gj(t) have their own values defined above in the worksheet.

Hi I have the following ln function that I want to differentiate wrt variable c:

I2 := -sqrt(-c^2+1)*ln(abs((.9*sqrt(-c^2+1)-c*sqrt(1-.9^2))/(-.9*sqrt(-c^2+1)-c*sqrt(1-.9^2))))

When I differentiate I obtain an expression that involves 

...abs(1, (.9*sqrt(-c^2+1)-.4358898944*c)/(-.9*sqrt(-c^2+1)-.4358898944*c))...

Why does it give a comma at the abs expression? how to get rid of that.

Hi I am using Maple 18 and am trying to make my looping work backward.

with(Student[Calculus1]);
with(linalg);
with(orthopoly);
Digits := 20;
n, K := 5, 4;
for k from 0 to n do a[k] := (int((T(2, t)-T(0, t))*T(k, t)/sqrt(-t^2+1), t = -1 .. 1))/Pi end do

First I use the above command to generate a0, a1, a2, a3, a4 and a5. Now i want to do a back substitute using the following recurrence relation to determine the values of b5, b4, b3, b2, b1 and b0.

b[n] := 0; (to find b5)

b[n-1] := a[n]; (to find b4)

(to find b3, b2, b1, b0)

Can someone assist me with the backward looping please. I does not seem to work.